Fields are overwritten when continuing simulation

[sigvaldm]

When continuing a simulation, the previously stored field data are lost. Probably this can be fixed by using an "append" mode in df::File or something.

[sigvaldm]

Actually I just had a brief look, and was unable to find something like an append mode in df::File.

[diakodarian]

Have a look at XDMFFile.h. It has this member function (latest version of FEniCS):

void write_checkpoint(const Function& u, std::string function_name, double time_step = 0.0, Encoding encoding=default_encoding, bool append=false);

which I presume it could be used to append to existing file. I couldn't test it to see if it works because in the FEniCS-version I'm using this function does not have the append argument. I'm also not sure if it will be more difficult to visualize the data with paraview.